For multibyte languages

Hi,

Could you please update following code;

$t = substr($t, 0, $c);

to

$t = mb_substr($t, 0, $c);

?

Without mb_, I got strange font overwrote in my Japanese contents.
I added it by myself but don’t want to rewrite it when plugin update.

Much appreciate if you arrange this short code for double-byted data. (Japanese, Chinese, Korean…)

Best,

Megumi